Heavy ion beam transport in an inertial confinement fusion reactor

Abstract

A new code, btrac, is under development to determine whether a beam of heavy ions can be focused to the necessary spot size radius of about 2 mm within an inertial confinement reactor chamber where the background gas densities are on the order of 10 14-10 15 cm −3 of lithium (or equivalent). Beam transport is expected to be strongly affected by stripping and collective plasma phenomena; if propagation is possible in this regime, it could lead to simplified reactor designs. The beam is modeled using a 2 1 2 -dimensional particle-in-cell (PIC) simulation code coupled with a Monte Carlo (MC) method for analyzing collisions. The MC code follows collisions between the beam ions and neutral background gas atoms that account for the generation of electrons and background gas ions (ionization), and an increase in the charge state of the beam ions (stripping). The PIC code models the complete dynamics of the interaction of the various charged particle species with the self-generated electromagnetic fields. Details of the code model and preliminary results are presented.